Recent advances in the diagnosis and treatment of natural killer/T-cell lymphomas

Introduction: Natural killer (NK)/T-cell lymphomas are aggressive malignancies that present predominantly in nasal and adjacent sites (nasal subtype), occasionally in skin, gastrointestinal tract and other tissues (non-nasal), and rarely as disseminated disease with a leukemic phase (aggressive NK-cell leukemia, or leukemia/lymphoma, subtype). Areas covered: The diagnosis and treatment of NK/T-cell lymphoma are discussed, based on a PubMed literature search. The diagnostic criteria for NK/T-cell lymphoma are highlighted, followed by an update of the diagnostic and prognostic importance (on presentation, at interim and end-of-treatment) of plasma EBV DNA as a surrogate biomarker of lymphoma load. Prognostic models based on clinicopathologic features and EBV DNA load are discussed. For stage I/II NK/T-cell lymphomas, combined chemotherapy, and radiotherapy gives the best results, with their concomitant or sequential administration equally efficacious. For stage III/IV NK/T-cell lymphoma, chemotherapy is the mainstay of treatment. Conventional anthracycline-based regimens for B-cell lymphomas are ineffective. Recommended regimens combine L-asparaginase with other drugs not affected by P-glycoprotein. For relapsed/refractory patients, immune checkpoint blockade with antibodies against programmed cell death protein 1 has shown much promise. Expert opinion: Current strategies result in durable remissions in a significant proportion of NK/T-cell lymphomas. Immune checkpoint inhibition and other novel approaches are promising for relapsed/refractory cases.